st: Cox "logrank" test after propensity score weighting

Hello,
I am comparing two treatment groups' survival after IPTW weighting on
a propensity score. The -sts test treatmentvar- command uses a
Cox-regression based comparison in this situation. I was wondering if
anyone has a citation that can be used to support this methodology
(other than the general statement that logrank test is not appropriate
with pweights) as used successfully in literature.
Wouldn't it be more appropriate to just run a multivariate Cox model
with other outcome-related variables?
Is this command still valid if the treatment variable does not meet
the PH assumption criteria?
Thanks for any insights,
Adam
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